An analytical model for the performance of the DOCSIS CATV network

The Data Over Cable Service Interface Specification (DOCSIS) is established as the primary cable network data communication standard in North America and is the first specification having reached international standard level. It is therefore appropriate to determine its performance. Previous works on performance analysis of the DOCSIS Community Antenna Television network have been carried out using computer simulations. In this paper, we propose a model for mini-slot allocation with two priority classes of traffic which supports a real-time Constant Bit Rate (CBR) service and a non-real-time data service. Real-time CBR traffic has pre-emptive high-over-line priority over non-real-time data traffic. The service discipline is First Come First Served. Two critical characteristics, average delay and throughput, are analysed. Finally, numerical results are presented. The results demonstrate that the delay requirement of real-time CBR traffic can be easily met at the expense of the delay of non-real-time data traffic.